Fire extinguisher



June 13, 1961 A. L. SMITH FIRE EXTINGUISHER Q 1 m2 %m a w w m w. A w 0MK MN Z m m f/ Z A %w Filed Aug. 1, 1957 United States Patent 2,988,150FIRE EXTINGUISHER Alonzo L. Smith, P.O. Box 6252, Houston, Tex. FiledAug. 1, 1957, Ser. No. 675,661 8 Claims. (Cl. 169-2) This inventionrelates to fire extinguishers and more particularly to automatic fireextinguishers to be associated with high pressure gas transmission linesand prevent or extinguish the fires which usually occur upon a break ina pipeline.

Present day gas transmission lines are 30 inches and 36 inches indiameter and utilize welded seam pipe having a wall thickness as low as0.312. Operating pressures in these lines are frequently as high as 800to 1200 pounds per square inch. These lines run into and through cities,industrial areas, parallel to railroads, through alleys, etc. Theselines are subject to corrosion, vibration, metal fatigue, andcontraction. Any of these and other problems could and do causeblow-outs or line breaks.

Where a line break occurs in a gas transmission line in a rural arealittle damage is usually done even if a fire occurs. Where a breakoccurs in a highly industrialized or populated area the gas may be blownfor many blocks and undoubtedly would be ignited in one of manydifferent ways. For instance pilot lights, sparks, or the like mayignite the gas. Sparks are perhaps the greatest danger in either ruralor urban areas due to blowing of rocks and other objects along theground by the gas as it leaves the pipeline.

A transmission line packed with gas will blow for a considerable timedepending upon the distance to the nearest compressor station. Thisblowing gas, when ignited becomes a tremendous blow torch and can causetremendous damage.

Block valves are used in some areas for operational shut-off purposes,but are not generally located on opposite sides of highly industrializedor populated areas. Even if the block valves are present the fire dangeris still tremendous as these valves will be located some distance apartand will require some time to close.

By this invention there is provided an automatic fire extinguisher whichwill deliver an atomized spray of fire extinguishing liquid such aswater at the location of the break regardless of where it occurs in thearea to be protected. This fire extinguisher functions automatically inresponse to conditions which are set up in the pipeline upon theoccurrence of a break. The fire extinguishing fluid will reach thelocation of the break immediately after the break occurs and willextinguish any fire which has started. The area will also be wet downthoroughly with fire extinguishing fluid to prevent the occurrence offurther fire as the line continues to blow.

It is an object of this invention to provide an automatic fireextinguisher for pipelines, particularly those which pass throughcongested areas.

Another object is to provide a fire extinguisher for pipelines whichautomatically blankets with fire extinguishing fluid the location of abreak in a line, wherever it may occur, immediately after the breakoccurs.

Another object is to provide a plurality of fire extinguishers whichupon the occurrence of a break, automatically blankets the area of abreak with successive charges of fire extinguishing fluid.

Another object is to provide a the extinguisher for a pipeline which isautomatically actuated upon the occurrence of a break in the line andwhich automatically blankets the area over which the escaping gas isbeing blown with fire extinguishing fluid.

Other objects, features and advantages of this invention will beapparent from the drawings, the specification and the claims.

In the drawings wherein there is shown by way of illustration oneembodiment of this invention and wherein like referenced numeralsindicate like parts:

FIG. 1 is a plan view of a section of pipeline employing two of the fireextinguishers of this invention;

FIG. 2 is an isometric view of a fire extinguisher constructed inaccordance with this invention;

FIG. 3 is a view along the lines 3-3 of FIG. 1; and

FIG. 4 shows the manner in which a pipeline passing through a congestedarea will be protected by one or more of the fire extinguishers of thisinvention.

Referring now to the drawings the gas transmission pipeline indicatedgenerally at 10 is protected by the fire extinguishers indicatedgenerally at 11.

The fire extinguisher includes a tank or extinguisher supply reservoirlocated closely adjacent the pipeline for supplying fire extinguisherfluid thereto. This tank may be of any desired form and may be locatedabove or below ground. Preferably, the tank is located below ground soas to not interfere with normal use of the ground surface. The tank ispreferably provided by a length of pipe which may be the same diameteras the pipe of the transmission line 10. The preferred pipe tank 12 isclosed at each end as shown at 13 and is laid parallel to thetransmission line 10. The volume of tank 12 is preferably large enoughto completely wet down the area of a break. By way of example for highpressure large diameter lines such as 30 inch pipelines it is preferredto use from 400 to 800 feet of 30 inch pipe to provide tank 12. 800 feetof 30 inch pipe would have a capacity of approximately 29,000 gallons ofwater. If the two extinguishers are installed in an area the volume ofwater to be released in the area would be approximately 58,000 gallonswhich would thoroughly wet down the area of a break and prevent fire.

The discharge of water from the tank should be automatic in response tothe occurrence of the break. The water discharged may be triggered inany desired manner by the abnormal conditions which exist in a pipelineupon the occurrence of a break. The two most prominent abnormalconditions are increased velocity and increased pressure drop along theline. It is preferred to use the pressure drop to automaticallydischarge the fire extinguishing fluid from tank 12.

Pressure drop in the line may be utilized to automatically triggerdischarge of fluid from tank 12 by connecting two lines 13 and 14 to thetank 12 and to the line 10 at spaced points. Thus the lines 13 and 14will reflect the pressure drop along pipeline 10 due to a break. As adrop of approximately one pound per hundred feet of pipe is not normallypossible between compressor stations in operation without a break thefire extinguisher may conveniently be triggered by a drop of, say, threeto ten pounds.

The pressure drop at which it is desired to trigger the fireextinguisher will govern the height to which portions of lines 13 and 14will extend above tank 12. Utilizing the well known physical phenomenonthat differential in pressure will raise a water column approximately 27inches per pound the portion 13a of line 13 and 14a of line 14 may beextended to the desired height to control the pressure drop at which thefire extinguisher will begin transferring fire extinguishing fluid tothe pipeline 10. It will be noted from FIG. 3 that line 13 has oneterminus 13b adjacent the bottom of tank 12. Thus if the line pressuredrops from line 14 to line 13 the gas within the line will enter throughline 14 and will force fire extinguishing fluid from the tank into thepipeline through line 13. Preferably both lines 13 and 14 have one endterminating at the bottom of tank 12 as shown in FIG. 3 to permitdischarge of fire extinguishing fluid in event of a break on either sideof the fire extinguisher. However it will be appreciated that one linemight have its terminus at the top of the tank to permit the tank tooperate in one direction only.

It will be appreciated that the diflerential in pressure will lift acolumn of fire extinguishing fluid to a predetermined height above thelevel of the fluid within the tank. Thus if the lines 13 and 14 aredesigned to permit the differential in pressure to just lift the fluidfrom the top of the tank to the height of portion 13a then as thepressure drop decreases the pressure differential might not besuflicient to drive the fire extinguishing fluid into the pipeline. Toavoid any possibility of not driving all of the fire extinguishing fluidinto the pipeline the height of portion 13a of line 13 as well as thesimilar portion 14a of line 14 may be designed to lift a column of fluidfrom the bottom of the tank to the height of portion 13a with a minimumdiflerential which would be present in the line until the fireextinguisher is emptied. As an alternative the tank may be located allor partly above the pipeline as illustrated in FIG. 3 and the siphonaction of fluid flowing between the tank and pipeline depended upon toempty the tank. Of course Where the tank is located above the pipelineand the fire extinguisher is triggered by operation of an automaticvalve the fire extinguishing fluid may be withdrawn from the bottom ofthe tank. The illustrated form is preferred however as there are nomoving parts involved which possibly might not function properly, norare there any valves which with time could become inoperative due tovalve members sticking in their seats.

The fire extinguishing fluid is preferably water but other fluids may beused if desired. Of course the design of lines 13 and 14 would be variedto accommodate fire extinguishing fluid of different density.

In the top of each tank 12 there is provided a fill valve 15. Also avent valve 16 opens into the top of each tank 12. Lines 13 and 14 areprovided with cutoff valves 17 and 18 respectively. When the tank needsfilling the cut-off valves 17 and 18 are closed and fill valve 15 andvent valve 16 are opened. The tank may then be filled in any desiredmanner as from tank cars. After filling, the vent valve and fill valveare closed and the two valves 17 and 18 opened. The extinguisher is nowin operative condition and upon a break in the line will introduce thefire extinguishing fluid into the pipeline. As the fire extingiushingfluid flows into the pipeline the high velocity gas will atomize thefluid and will carry it to the break in the form of an entrained fog.The water or other fluid will therefore be carried by the gas over thearea which is blanketed with gas and this entire area will be wet downto extinguish and prevent fires.

Referring now to FIG. 4 this invention is shown in a typical applicationto a congested area such as an industrial area. A fire extinguisher 19is provided for the pipeline on one side of the area and a secondextinguisher 20 is provided on the other side of the area. If a breakoccurs in line 10 any where between the two fire extinguishers 19 and 20such as at 21 both extinguishers 19 and 20 will discharge fireextinguishing fluid into the pipeline and it will be carried by gas tothe break 21 to fog the area. It will be appreciated that the chargesfrom the two fire extinguishers may reach the break in partsimultaneously but will in part discharge successively to provide acontinuous spray. The successive discharge from the two fireextinguishers will be more apparent if the break is closely adjacent oneof the extinguishers. It will also be appreciated that the fireextinguishers could be positioned in banks of two or more on one or bothsides of the congested area.

The gas within the conduits l3 and 14 will normally be stagnant andtherefore there will be little or no tendency for the gas in thepipeline to absorb water from tank 12. However, if desired, a barriermay be inserted in each of these lines such as a frangible member or abarrier trap of the conventional U tube type filled with glycerin.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes may be madewithin the scope of the appended claims without departing from thespirit of this invention.

What is claimed is:

1. A gas pipeline fire extinguisher comprising, a pipeline to beprotected, a pipe for containing extinguisher fluid, said pipe closed atboth ends to provide a tank and laid underground alongside the pipelineto be protected, two conduits connecting the tank to the pipeline forfluid communication at points sufliciently spaced to reflect a pressuredrop along the line with abnormally high velocity flow in the line, eachof said conduits having a portion positioned above the tank and at leastone of the conduits terminating adjacent the bottom of the tank, theheight of said portion of each of the said conduits which terminatesadjacent the bottom of the tank being positioned above the normal fluid'level within the tank by an amount which a column of extinguisher fluidwill be raised by the differential in pressure between said points atwhich it is desired to begin injecting extinguisher fluid into thepipeline.

2. A pipeline fire extinguisher for a pipeline extending through acongested area comprising, a pair of tanks each provided by a closed endconduit laid alongside the pipeline to be protected, one tank being laidon each side of the congested area, a pair of conduits connecting eachtank to the pipeline at points sufliciently spaced along the pipeline toreflect a pressure drop along the line with abnormally high velocityflow in either direction in the line, each of said conduits terminatingadjacent the bottom of a tank, each of said conduits having portionspositioned above the tank by an amount equal to the height of a columnof water which will be supported by a pressure diiferential equal to thepressure differential between the conduits of each of said pair at whichit is desired to inject Water into the pipeline.

3. A pipeline fire extinguisher system comprising, a pipeline to beprotected, a tank for containing extinguisher fluid adjacent thepipeline, means connecting the tank to the pipeline and preventing flowof fluid from the tank to the pipeline while fluid flow in the pipelineis below a predetermined velocity, said means sensing pressure in saidpipeline at points sufliciently spaced to reflect a predeterminedpressure drop along the pipeline when fluid flow therein exceeds apredetermined normal velocity and operable in response to fluid flow inthe pipeline above said predetermined normal velocity for transferringfluid from the tank to the pipeline.

4. A pipeline fire extinguisher system comprising, a pipeline to beprotected, a tank for containing extinguisher fluid adjacent thepipeline, fire extinguisher fluid in said tank, means connecting thetank to the pipeline and preventing flow of fluid from the tank to thepipeline while fluid flow in the pipeline is below a predeterminedvelocity, said means sensing pressure in said pipeline at pointssufficiently spaced to reflect a predetermined pressure drop along thepipeline when fluid flow therein exceeds a predetermined normal velocityand operable in response to fluid flow in the pipeline above saidpredetermined normal velocity for transferring fluid from the tank tothe pipeline.

5. A pipeline fire extinguisher system comprising, a pipeline to beprotected, a tank positioned alongside the pipeline, two conduitsconnecting the tank to the pipeline at points sufliciently spaced toreflect a predetermined pressure drop along the pipeline when fluid flowtherein exceeds a predetermined normal velocity, said conduits havingportions positioned above the tank, one of said conduits terminating inand adjacent the bottom of the tank, at least one of said portionspositioned above said conduit terminus in the tank by a distance atleast equal to a column of fire extinguisher liquid which will besupported by the pressure differential in the pipeline at saidconnections when fluid flow in the pipeline is flowing at said normalvelocity but not more than a distance equal to the height of a column offire extinguisher fluid which will be supported by the pressuredifferential in the pipeline at said connections when fluid How in thepipeline exceeds said normal velocity by a predetermined amount.

6. The system of claim 5 wherein both conduits terminate adjacent thebottom of the tank and have portions above the tank at approximately thesame elevation.

7. The system of claim 5 wherein the tank is located at least in part ata higher elevation than the pipeline whereby once flow commences throughsaid conduits such flow will continue through a siphoning action.

8. A pipeline fire extinguisher comprising, a pipeline to be protected,a tank alongside the pipeline to be protected, two conduits connectingthe tank to the pipeline at points sufiiciently spaced to reflect apressure drop along the line with a predetermined abnormally highvelocity flow in the line, at least one of said conduits having aportion positioned above the tank and terminating adjacent the bottom ofthe tank, the height of said portion being suflicient to prevent flow ofliquid from the tank to the pipeline due to the pressure differential atsaid points when the velocity of flow in said pipeline is not greaterthan a predetermined normal velocity but not enough to prevent flow ofliquid from the tank due to the pressure diflierential at said pointswhen the velocity of flow in said pipeline increases above said normalvelocity to said predetermined abnormally high velocity.

References Cited in the file of this patent UNITED STATES PATENTS1,640,839 Kliewer Aug. 30, 1927 2,141,591 Bonner Dec. 27, 1938 2,178,519Gill Oct. 31, 1939 2,327,335 Boerner et a1 Aug. 24, 1943 2,606,690Hansen Aug. 12, 1952 2,707,480 Klosse May 3, 1955

